DearFriend,
I would be grateful if somebody give an opinion on my problem regarding 1998 E 200 W210.
Firstly I am sorry for my english.
My 210 seem to have a problem with her engine rpm especially during idling/stopping at traffic light etc for the last few days.The rpm would cries up and down and most of the time the engine would be dead and caused a sweaty driver's armpit...(haha).It occur for most of the time during stopping at D/R/321 gears.
During running position the rpm would be accordingto my push on engine trottle, only on rare occassion they losing coordination for a very brief seconds.
The car had been running for 290,000km and a top engine overhaul has been done 5000 km ago.
Thank you for any opinion.

 

Hello again, I want to add something,
A few hours ago I did bring the car to the mechanic and they had clean the throttle body but did not heal the symptom.They suggest for throttle body replacement.
Now I am thinking for other possibility.(since any mechanic would suggest for a replacement other then givingidea why it did malfunction and try to be mc gyver)
I had no knowledge on cars and their mechanic so I need any of your opinion.
I am thinking of electronic malfunction.The car had a history of overheating 5000km ago for a leaking water jacket and need a top overhaul.She was ok after that than a radio problem arised...the volume of audio would adjusting itself to zero afterturning on the radio/cd.I ignore the problem till now.Then central locking problem arised in which the car could not be locked initially at the front passenger site then including all locks.I was thinking of vaccum pump failure and not yet get the problem solved.Then the missfire especially at idle speed come out.My theory is the ECM-could it be a previous overheating had made the cumputer hang and setting up wrongly??but against this is the gradual 'chain of failure'
I did come about with tba(throttle body allignment), but I am too idiot to understand what it is.
Do somebody think that it is the 'electronic malfunction; rather than tb total failure??

 

Update.,
No reply from anyone yet.,maybe this problem was discussed somewhere else and no longer attract for an opinion.Anyway This morning I brought the car for a STAR diagnostic a MB sales N service appointed dealer.,The faulty code suggest MAF sensor /fuel filter, and they say the throttle body looks ok but would be considered if changing the MAF sensor do not solve the problem.Now I am waiting for the price list as they could check it today for internet connection problem, but they give a rough figure of 600-700USD.(I did look at ebay but no maf sensor for my model-other model maf sensor qoutes only around 100-230USD!)
After reached home with a few times stall at traffic I did disconect the MAF sensor connector.What is good, the RPM do not fluactuate at idle speed, only coming down less than 5000 but then recover quickly to 7000 after stopping from running wheels.The fluactuation was less than before (only one fluactuation from running to idle)and not bouncing hard.I come across for an idea of cleaning the maf sensor (even this is not suggested by a few expert).I did clean the sensor with crc and assemble them again.It does not solve the problem.
Now can someone tell me why after disconnected the sensor the problem lessen, and do it create more problem later if I run the wheels with disconected maf sensor while waiting for a change?
Thank you.

 

Ending a drama-till now.
Change MAF sensor(for 180USD).
Breathe GOOD.,no erratic fluactation,no stalling at idle, no losing rpm during acceleration.
Minor problem (RPM) noticed after 5 minutes put in idle, RPM slightly below 500 then recover, only once a while.There are various item responsible for a smooth engine running,
One lesson for newbie like me.,think maf sensor(esp w210) on fluactating rpm...and the list wouldcontinue till you solve the problem.